Friday, November 16, 2007

The Day Sky

Last week the entry wasn’t all that educational. That is why this week I am going to try my best to teach something. Let’s see, I could blog about why the grass is green. Although it is a complex process it doesn’t interest me. I am going to continue with the concept of the sky from a few weeks ago. This time, however, I will focus on the day sky.

Most of us don’t think much of the day sky. Yet, it is important to know certain things about it. Why the sky is blue is something that we all should know. The smart mouths will be quick to say it is because of the atmosphere. That is true, but it is not the complete answer.

Sunlight travels to Earth and comes in contact with the atmosphere. In the atmosphere there are gas and dust particles in the air. It happens that blue light is the one affected by these particles. The dust particles are bigger than the blue light waves and smaller than the red light waves. The blue light is scattered in all directions by these particles in the air. Simply, the blue in the sky we see is scattered blue light.

Then why are sunrises and sunsets red? The sunlight has to travel through more atmosphere, meaning more particles in the air, compared to when it is directly above us. The blue light and all other colors are scattered so much that only red, orange, and yellow light remains visible. I hope it makes sense and good luck retaining the information.